More than 20 years since making a rock concept record, Roger Waters tells Rolling Stone he has finished a song for an album tentatively titled Heartland. Completed on lunch breaks during the elaborate Wall tour that ended in July, the untitled song confronts what Waters calls "religious extremism."

"I'm not sure what it will be called," Waters said in an interview Monday in Manhattan, where he will perform at the Bob Woodruff Foundation's Stand Up for Heroes benefit, part of this week's New York Comedy Festival. "I'll tell you what the first line is – I haven't told anyone else, and I may be sticking my head too far above the parapet – but the first line is, 'If I had been God . . . '"

Waters, who last referenced God outright on 1992's Amused to Death in the three-part song "What God Wants," said this song was just what he needed to move forward with Heartland.

"The Heartland idea sort of came from another song I wrote maybe 15 years ago, or longer even, which was a song that I wrote for a movie – a really, really bad movie called Michael that was about an angel," Waters said. "I'm absolutely determined to make another album. And I think this new song may give me the chance to do that. It provides a cornerstone and a core idea for me to write a new album about. You know, it's just one of my obsessions, which is, I'm sort of obsessed with the idea that religious extremism is a maligned factor in most of our lives."

Waters' other obsessions – themes of battlefield bloodshed, threatened liberty, isolation and madness – have advanced much of his solo work beyond Pink Floyd, though he confirmed his next album will not feature former bandmates David Gilmour and drummer Nick Mason. Waters last recorded with the group, excluding Richard Wright, on 1983's anti-war opus, The Final Cut.

That album opened with "The Post War Dream," the idea of which "is somewhat in tatters" in the real world, Waters said. "But having said that, it is developing in other parts of the world . . . We are determined to continue to fight against the onslaught, if you like, of a society driven mad by the headlong rush to maximize the bottom line."

Long known for his condemnation of war yet strong devotion to troops worldwide, Waters will rehearse with a band of wounded veterans he recruited from Walter Reed National Military Medical Center prior to Hurricane Sandy. Eight soldiers and three Marines will join him for three songs, including Pink Floyd's "Wish You Were Here," at Thursday's Stand Up for Heroes benefit at Beacon Theatre, which will also include performances from Bruce Springsteen and John Mayer.

"These guys are good," Waters said of his recruits. "I'm really proud to be working with them."